Adcice on removel & maintenance of car seat type angle adjuster

[jkn]

Hi all I have a special 'posture chair', part of whose construction is derived from a car seat. There is a large 'turnwheel' on one side which you can turn to adjust the angle of the seat - similar to how you'd adjust the slope of the backrest when in a car.

This chair is a good twenty years old now and a fair bit of play has developed in this adjustment - at any one setting you can move the seat by maybe 10 degrees up/down by hand.

I would like to improve this if possible but don't know how such a mechanism works internally. There is a slotted nut holding the turnwheel on, but I am a little nervous of it holding in some pingfuckits or similar.

Any pointers to how these mechanisms work, and/or advice on removal and servicing?

Thanks, J^n

[Brian Gaff (Sofa]

Maybe its a bit like the garden lounger chairs, a simple ratchet that has a slight bias so it unhooks as you move the back back upright a bit?

Brian

[Harry Bloomfield, Esq.]

jkn formulated the question :

They use cogs, formed as pressed steel, pressings. They are not really designed for too regular use and if over used they will wear and eventually start to slip. Not much can be done with them, other than replacement.

[jkn]

Hi - thanks for the reply (and apologies for not checking for typos in the posted title!)

What you say sounds very plausible; I may leave well alone. It is a minor annoyance and unless I can source an alternative fitting (the chairs are no longer made) it is probably not worth fiddling too much.

Regards, J^n

[newshound]

But both for the car seat and the domestic application, backlash is not really an issue since, when in use, it it taken up by the applied load.

[jkn]

Yes for the car seat - but for this seat the adjustment is for the horizontal plane (there is no back) and it ends up with the seat base being able to 'rock' somewhat, which is not what I want.